1. Technical Field
This invention relates generally to static gaskets of the type used to establish a gas/fluid-tight seal between two members to be clamped together and to their method of construction.
2. Related Art
In establishing a gas/fluid-tight seal between two members to be clamped together, such as a cylinder head and engine block, it is common to use a static cylinder head gasket having multiple layers. Generally, at least one of the layers of the multilayer gasket, sometimes referred to as a functional layer, has one or more seal beads to establish a gas/fluid tight seal about openings, such as cylinder bores, coolant openings, and/or bolt openings. Another of the layers, sometimes referred to as a distance layer, is configured to abut the functional layer to facilitate establishing the gas/fluid tight seal about the openings by limiting the compression of the seal beads of the functional layer.
To facilitate compressing the seal beads of the functional layers to the desired height, without over compressing the seal breads, the distance layer is typically formed having raised protrusions formed within the material of the distance layer. The raised protrusions are typically formed in a coining process via a high tonnage forming press. As such, the press plastically deforms the material of the distance layer to form the raised protrusions. Unfortunately, the high tonnage presses used to form the raised protrusions are very expensive, occupy of a large amount of space, and upon being set-up, are dedicated to a specific size and pattern of raised protrusions, thereby requiring a great deal of time and effort to change from one pattern of raised protrusions to another. Further, as a result of plastically deforming the material of the distance layer, the material properties are altered in an unpredictable manner, thereby creating, within the material of the distance layer, unpredictable material properties, which ultimately can lead to premature failure of the distance layer's ability to function as intended. Further yet, having to mechanically upset the material of the distance layer typically results in the raised protrusions having shapes and sizes deviating from the shape and size actually desired, mainly due to tolerances within the distance layer material, as well as tolerances of the press and tools used to form the raised protrusions.